From: jsg <jsg@openbsd.org>
Date: Thu, 30 Nov 2023 02:47:39 +0000 (+0000)
Subject: drm/i915: Fix potential spectre vulnerability
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=995354c8e016d5c109f34ab0b320a8ae2d19e773;p=openbsd

drm/i915: Fix potential spectre vulnerability

From Kunwu Chan
07e94f204f38b0d36eb377b3cda088b4a8b6f9a2 in linux-6.1.y/6.1.64
1a8e9bad6ef563c28ab0f8619628d5511be55431 in mainline linux
---

diff --git a/sys/dev/pci/drm/i915/gem/i915_gem_context.c b/sys/dev/pci/drm/i915/gem/i915_gem_context.c
index 92711306e0b..2057278c2c5 100644
--- a/sys/dev/pci/drm/i915/gem/i915_gem_context.c
+++ b/sys/dev/pci/drm/i915/gem/i915_gem_context.c
@@ -852,6 +852,7 @@ static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
 		if (idx >= pc->num_user_engines)
 			return -EINVAL;
 
+		idx = array_index_nospec(idx, pc->num_user_engines);
 		pe = &pc->user_engines[idx];
 
 		/* Only render engine supports RPCS configuration. */